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    Please do not post a support request without first reading and following the advice in https://retropie.org.uk/forum/topic/3/read-this-first

    Strange Issue with CRT

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    raspberry piretropiearcade240poverscan
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    • M
      maxriptide @Galaga
      last edited by

      @galaga the configuration is correct. Make sure to disable any overscan setting, if the problem is still present you may have to tweak some geometry potentiometer in your monitor board.

      GalagaG 1 Reply Last reply Reply Quote 0
      • GalagaG
        Galaga @maxriptide
        last edited by

        @maxriptide I've tried messing with the overscan settings but nothing would change. And when I tried adjusting the monitor, the picture would move but it would still look cut off. It never did this on the original PCB so I'm guessing it's the Pi being stupid. Oh well :(

        edmaul69E 1 Reply Last reply Reply Quote 0
        • edmaul69E
          edmaul69 @Galaga
          last edited by

          @galaga does your monitor have a switch somewhere on the board that lets you switch between 15khz and and something like 24 or 31khz on it? It could be anywhere on the board or if your controls are on a seperate board it could be on that.

          GalagaG 1 Reply Last reply Reply Quote 0
          • GalagaG
            Galaga @edmaul69
            last edited by

            @edmaul69 The monitor is definitely 15Khz, and the JPAC is set for that too.

            edmaul69E 1 Reply Last reply Reply Quote 0
            • akafoxA
              akafox
              last edited by

              I use and old CRT on for my raspberry pi 3 here is my settings:

              1. This is setup of a NTSC crt tv your settings will differ based on your country
              2. The bolded info is one that solved my problem
              3. This is for crt TV NOT an arcade monitor I am not responsible for any damages!

              (More here: raspberry pi config.txt)

              #uncomment for composite PAL
              sdtv_mode=0
              sdtv_aspect=1
              overscan_scale=1

              #uncomment this if your display has a black border of unused pixels visible
              #and your display can output without overscan
              #disable_overscan=1

              #uncomment the following to adjust overscan. Use positive numbers if console
              #goes off screen, and negative if there is too much border
              overscan_left=10
              overscan_right=10
              overscan_top=-8
              overscan_bottom=-4

              #uncomment to force a console size. By default it will be display's size minus
              #overscan.
              framebuffer_width=720
              framebuffer_height=480

              People want things easy...but then complain that life is boring...

              edmaul69E GalagaG 4 Replies Last reply Reply Quote 0
              • edmaul69E
                edmaul69 @akafox
                last edited by

                @akafox he has to do the 320x240 mode not 640x480 because of his 15khz arcade monitor

                akafoxA 1 Reply Last reply Reply Quote 0
                • edmaul69E
                  edmaul69 @Galaga
                  last edited by

                  @galaga can you look and see if any caps are blown? I think this might be a problem with the monitor and not the pi. Even if the original game board you used didnt show an issue. Its been a good many years since i worked on arcades so i am fuzzy on the cause but it is something i have seen before.

                  GalagaG 1 Reply Last reply Reply Quote 0
                  • akafoxA
                    akafox @edmaul69
                    last edited by

                    @edmaul69 I am aware of that...I just didn't know the resolution settings for the monitor.

                    Question..will the pi burn out a arcade monitor like it will an old crt TV?
                    Or is an arcade monitor more "like a PC monitor"?

                    People want things easy...but then complain that life is boring...

                    M 1 Reply Last reply Reply Quote 0
                    • GalagaG
                      Galaga @edmaul69
                      last edited by

                      @edmaul69 I haven't taken the chassis out but I can't see anything wrong. I've never replaced caps on anything before so doing a cap kit is really scary lol. You think I should take it out anyways?

                      1 Reply Last reply Reply Quote 0
                      • GalagaG
                        Galaga @akafox
                        last edited by

                        @akafox I will try adding the overscan parts in config.txt and see what happens.

                        1 Reply Last reply Reply Quote 0
                        • M
                          maxriptide @akafox
                          last edited by maxriptide

                          @akafox while pc monitors (multisync monitors) are usually protected against out-of-spec signals and may display a message such as "signal out of range", an arcade monitor may be damaged if an out-of-spec signal is sent to it. If you see a scrambled image on your monitor you'd better switch it off as soon as possible.

                          Adding overscan will prevent you from getting a pixel-perfect image.

                          1 Reply Last reply Reply Quote 0
                          • GalagaG
                            Galaga @akafox
                            last edited by

                            @akafox said in Strange Issue with CRT:

                            overscan_left=10
                            overscan_right=10
                            overscan_top=-8
                            overscan_bottom=-4

                            I added those lines in config.txt and it made no change :(

                            1 Reply Last reply Reply Quote 0
                            • GalagaG
                              Galaga @akafox
                              last edited by

                              @akafox Actually I added the framebuffer lines under the overscan lines (used 320 and 240) and it fixed the issue! But only in the terminal...

                              1 Reply Last reply Reply Quote 0
                              • GalagaG
                                Galaga
                                last edited by

                                Any suggestions?

                                1 Reply Last reply Reply Quote 0
                                • akafoxA
                                  akafox
                                  last edited by

                                  strange..are using advmame? you might have to tweak the settings in the admame.rc

                                  People want things easy...but then complain that life is boring...

                                  GalagaG 1 Reply Last reply Reply Quote 0
                                  • GalagaG
                                    Galaga @akafox
                                    last edited by

                                    @akafox No, RetroPie is completely ignoring the config.txt settings...

                                    1 Reply Last reply Reply Quote 0
                                    • GalagaG
                                      Galaga
                                      last edited by

                                      Ok I think I finally fixed it to the point where it doesn't make me angry. I decided to try someone else's config.txt as mine was cursed or something :P I went here: https://www.dropbox.com/sh/6hdpa7893c3ked1/AABCXqUHjXI-C3PUdcq4f8jya?dl=0 and downloaded the "custom_res" config. I renamed it to "config.txt", changed the resolution to 320x240, and added some custom overscan numbers. The lines are still there, but they don't affect the text and only appear on a black screen. I'm sure I could go further and 100% fix it but right now I'm happy. Whew!

                                      1 Reply Last reply Reply Quote 0
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